Trampling Charge. If the triceratops moves at least 20 feet straight toward a creature and then hits it with a gore attack on the same turn, that target must succeed on a DC 13 Strength saving throw or be knocked Prone. If the target is Prone, the triceratops can make one stomp attack against it as a bonus action.
Gore. Melee Weapon Attack: +9 to hit, reach 5 ft., one target. Hit: 24 4d8+6 piercing damage.
Stomp. Melee Weapon Attack: +9 to hit, reach 5 ft., one Prone creature. Hit: 22 3d10+6 bludgeoning damage.